disc grinder and motor control help

J

JMJones

Well-Known Member
I recently recieved a great deal (free) 1/2 hp DC Baldor motor from a friend/steelbaron. I want to make a disc grinder that is variable speed and reversible. Can anyone look at this motor and tell me what kind of controller/ vfd that I need to make that happen. Here are the pics and I can provide any other details if needed. Your help is greatly appreciated. I have posted this question in a few forums becausen I want to get as many informed opinions as possible.


motor1.jpg


motor2.jpg
 
It looks like a great motor. Id like to see the wiring diagram on it...becuase it looks like you have your choice of 180/200/100 volts dc. The 100 volts DC will come from a DC controller if you input 120VAC. The 180VDC will come from the controller if you input 220VAC.

You need DC speed control..a small one for 1/2 hp. Then set up the controller for 110V ac input so you can plug it in the wall....make your your motor can be wired for the 100V DC input and you're all set.

-Rob
 
I will get a pic of the wiring diagram and post it soon. I should also add that I dont really mind adding a clean box if it will cut down the price of the controller significantly.
 
I wired up a tig welding foot control to my disc sander, that way you can keep both hands on what you are doing and still have variable speed.
 
rfrink said:
It looks like a great motor. Id like to see the wiring diagram on it...becuase it looks like you have your choice of 180/200/100 volts dc. The 100 volts DC will come from a DC controller if you input 120VAC. The 180VDC will come from the controller if you input 220VAC.

You need DC speed control..a small one for 1/2 hp. Then set up the controller for 110V ac input so you can plug it in the wall....make your your motor can be wired for the 100V DC input and you're all set.

-Rob
Click to expand...

I speak motor:D This is a 180 volt DC motor, the 200/100f are the field voltages and depends on whether you wire the field windings in series or parallel. When wiring most controllers at 110V you will get 90VDC at 220V you get 180VDC. Some thing similar to this WU-70100-10 from www.coleparmer.com would work it is a Basic Variable-Speed DC Motor Controller for 1/4 to 2 hp motors. Or you could Try www.minarikdrives.com and save $50 but you need to ad an enclosure a potentiometer and wire up the switches. You might find one cheaper elsewhere but those are some of my faves. The separate field windings are brought out for more complicated control options like over speeding and field quenching which you will probably not need. As for reversing you will probably need to wire in a switch that reverses the polarity of the armature because most basic speed controllers are ...well... Basic!
 
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No it does not reverse on its own. But you can wire in a 2 pole 3 position toggle switch in the armature circuit to reverse the polarity. Just don't throw the switch wile the motor is moving or you will blow fuses.
 
Sorry but you still need 220V for this controller to run your motor at full speed. You can run it with 120V but your motor will run at half speed. Or if 220V is absolutely not an option then you could use a 2:1 transformer to step up the voltage. The switch is a great way to control the direction though.
 
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